Using version control data to evaluate the impact of software tools: a case study of the Version Editor

Software tools can improve the quality and maintainability of software, but are expensive to acquire, deploy, and maintain, especially in large organizations. We explore how to quantify the effects of a software tool once it has been deployed in a development environment. We present an effort-analysis method that derives tool usage statistics and developer actions from a project's change history (version control system) and uses a novel effort estimation algorithm to quantify the effort savings attributable to tool usage. We apply this method to assess the impact of a software tool called VE, a version-sensitive editor used in Bell Labs. VE aids software developers in coping with the rampant use of certain preprocessor directives (similar to #if/#endif in C source files). Our analysis found that developers were approximately 40 percent more productive when using VE than when using standard text editors.